Tuesday, June 19, 2007

THE PALE MALE NEST SYMPOSIUM IS NOW OPEN

Pale Male and Lola look at their third set of failed eggs. They wait for a solution because what has happened is beyond their ken. They are doing everything they've done before but it isn't working. It's been three years since humans destroyed Pale Male's many year run of successful nests. Now it's time for humans to mend what they have wrought.

I T' S Y O U R T U R N !

WE'VE ALL TALKED IT OVER FOR THREE YEARS. NOW IS THE TIME FOR YOU TO HAVE YOUR SAY. DO YOU HAVE A NEW THEORY? DO YOU AGREE WITH ONE OF THE EXISTING THEORIES? WRITE AND EXPLAIN WHY. HOW ABOUT A UNIQUE WAY TO FIX THE PROBLEM EXPRESSED IN ONE OF THE CURRENTLY HELD THEORIES? DO YOU FEEL IT IS A COMBINATION OF PROBLEMS. LET US HEAR IT.

THIS IS A PUBLIC FORUM IN SEARCH OF AN ANSWER. GO FOR IT!

SEND EMAIL FOR POSTING. THE COMMENTS SECTION IS TOO LIMITING.

PHOTOGRAPHS, DIAGRAMS, AND VISUAL AIDES? BRING THEM ON.

First up in no particular order, we put forth the Venturi Effect. As explained in this email from the archives of palemale.com from Dale, an engineer, and a NJ member of Audubon.

By the way Dale, we'd love to talk to you about this, get in touch.

Here is what Dale had to say-

Last year I wrote...about the problem with Pale Male and Lola's nest. Some background info: I'm a member of the NJ Audubon (and an engineer) and noticed a problem with the nest support that you made for the nest. Talking to fellow members in NJ, we agreed that the most likely cause of the eggs not developing past the early stage is the lack of incubation since there was no evidence of chemical contamination or deformity of the fetus. The support on which the nest sits has the shape that could cause a venturi effect and accelerate the air flow under the nest. If this happens, the eggs will cool from the bottom and no amount of incubation by the birds will help.

The old support rested on the concrete and prevented this effect. Another clue can be found in the birds themselves. They tried to add a significant layer of nesting material after the eggs were laid which to my knowledge is not normal behavior. They seemed to realize the problem too late.

Last year you... stated that they [Red-tails] build nests on tree branches with open bottoms. Unfortunately, that is not an entirely true statement. They build the nest usually in a branch Y with the bottom supported. Even if there is an exposed portion of the nest, the tree branch blocks the wind. It's not like your nest support which channels the wind and makes the wind stronger. This year (for the third time), the same exact problem occurred with the same behavior. I was hoping that they would move their nest site but I guess that they are stubborn. As suggested last year, you can remedy the air flow problem by attaching something below the rack to block the wind such as hard plastic sheeting. leave enough room to allow water drainage or you will swamp the birds when it rains.

From a concerned member.

Dale

Pale Male and Lola's nest as of March 22, 2007 3:46PMIs it only the lack of enough nesting materials even in the third year?

And for those that would like another look at the cradle while they muse over their theory, their fix, or their response to a previous theory. Here it is right before installation.

John Blakeman's visual aid to show the height of the spikes within the nest, to help explain his proposition that the pigeon spikes should be clipped within the bowl of the nest. He theorizes that they may be causing a disruption either by wicking heat away from the eggs or by interfering with normal egg manipulation by the hawks.

Pale Male is looking. You too take a closer look at all that metal that now resides above the cornice conceivably drawing heat away from the eggs.

Also note the more modern spikes above Pale Male's head as opposed to the earlier rendition that was installed on wood flush with the masonry cornice.

Was a switch made?

The Fordham installation of pigeon spikes. In my memory these are very similar spikes and installed the same way, on wood, flush against the building as was the foundation for Pale Male's original nest before it was destroyed.

The current spikes, original or not, no longer have the solid wooden foundation. (Look above you can see through the cradle, the solid buffer of the wood and the cornice itself are gone. That's a big change.) The spikes are now directly attached to the cradle, metal to metal, capable of wicking heat away from the eggs. Turning the cradle into a very large cooling device to dissipate heat. Similar to the coils on a refrigerator.

1 comment:

Anonymous
said...

In the case of the nest at Fordham, I don't believe the spikes are attached to wood, but are simply nailed or riveted to the stone or masonry surface of the pediment. But it's a very narrow strip, and it's out at the very edge of the broad horizontal cornice. Very ineffective in repelling pigeons, if you ask me.

But when Hawkeye and Rose began laying down sticks, these spikes worked very well in terms of securing them in place, while not coming into contact with the eggs in any way, because the eggs were laid in the center of the nest, and the spikes were out at the edge. And of course, this indirectly turned out to be a very effective way of repelling pigeons from that ledge, but they still nest all over Collins Hall. Overall, there are fewer pigeons on the campus, though.

In the case of the Fordham nest, the sticks are sitting directly on the cornice, and the spikes are out at the very edge, and probably not affecting the eggs at all.